Torild van Eck

Robust automatic P-phase picking : an on-line implementation in the analysis of broadband seismogram recordings

Abstract The onset of a seismic signal is determined through joint AR modeling of the noise and the seismic signal, and the application of the Akaike Information Criterion (AIC) using the onset time as parameter. This so-called AR-AIC phase picker has been tested successfully and implemented on the Z-component of the broadband station HGN to provide automatic P-phase picks for a rapid warning system. The AR-AIC picker is shown to provide accurate and robust automatic picks on a large experimental database. Out of 1109 P-phase onsets with signal-to-noise ratio (SNR) above 1 from local, regional and teleseismic earthquakes, our implementation detects 71% and gives a mean difference with manual picks of 0.1 s. An optimal version of the well-established picker of Baer and Kradolfer [Baer, M., Kradolfer, U., An automatic phase picker for local and teleseismic events, Bull. Seism. Soc. Am. 77 (1987) 1437–1445] detects less than 41% and gives a mean difference with manual picks of 0.3 s using the same dataset.

Setting up a virtual broadband seismograph network across Europe

European seismological observatories have undergone an impressive evolution in the last 5 to 10 years. The result is a very dense, but patch-like coverage, with seismic instruments operated by a multitude of different observatories. Providing the research community with easy and rapid access to all of these waveform data poses a significant challenge. An ongoing European Community-funded project, Mediterranean-European Rapid Earthquake Data Information and Archiving Network (MEREDIAN), aims to shape these national efforts into a European-Mediterranean infrastructure for broadband waveform data exchange and archiving.

Networking Research Infrastructures for Earthquake Seismology in Europe

In the past decade, European countries have experienced a surge in funding, of the order of 100 million euro (€100 million), for new earthquake monitoring equipment and initiatives. Permanent and mobile seismograph and accelerometer networks on national, regional, and global levels are being modernized and are expanding at a significant pace. Currently, earthquakes in the European-Mediterranean region are recorded by more than 2500 short-period (SP) seismometers, 3000 accelerometers, and 800 broadband (BB) permanent seismic stations operated by more than 100 networks and observatories. An additional 400 BB and more than 1200 SP mobile stations are deployed by universities and research institutes in temporary experiments. This unprecedented and still-expanding recording capacity in Europe and its immediate surroundings opens up new research opportunities as well as new data-handling challenges. For example, maintaining optimum access to the data and integrating facilities with different types of data require a high level of networking and coordination.

ORFEUS, a European initiative in broadband seismology: status and future plans

Abstract Observatories and Research Facilities for European Seismology (ORFEUS) is the European initiative for the coordination of broadband seismology in Europe and the Mediterranean area. The organization is unique in its field, because it does not operate any stations, but acts as an intermediate between data users and data producers. The core activity of ORFEUS is the operation of a data center, which archives seismic waveform data of large seismic events and offers both off-line (CD-ROM) and on-line (Internet, WWW) access to both the archived data and global near real time Spyder® data. ORFEUS coordination function is largely realized through its working groups and web site, which presently provide, among others, station siting and equipment overviews, technical information and support and a Seismological Software Library (SSL). Cooperation with other centers, for example, on data formats, is coordinated through the Federation of Digital Seismograph Networks (FDSN). Future developments emphasize improved data access through the Internet (WWW, Automatic Data Request Manager, NetDC protocol) and a regional version of the Global Spyder®: EuroSpyder. Regularly, work meetings and workshops are organized to discuss future developments and its impact on ORFEUS.

Integrating the European Observational Seismology Infrastructure: NERIES Developments

Europe and its surroundings operate an impressive number of seismometers and accelerometers, accommodating high and lower quality sensors, permanent and mobile stations, land-based and ocean bottom systems. The equipment and observatories are largely funded by national resources and priorities. Recently a number of initiatives, among them NERIES , have accomplished a significant step towards integrating this diverse network into a homogeneous real-time network, data archival and data access facility, thus providing a powerful research tool for future earth science research and hazard assessment.

85.4 – ORFEUS Seismological Software Library

This chapter focuses on Observatories and Research Facilities for European Seismology (ORFEUS) Seismological Software Library, whose main aim is to provide an organized overview of the software made available in the academic community either through the Internet (Web sites or FTP) or on personal request. The Library is presently divided into four sections, which include software links, PC-shareware links, conversion software, and Java/CORBA links. The PC-shareware links is a further development of the International Association of Seismology and Physics of the Earths Interior (IASPEI) PC Shareware Library initiated. The IASPEI PC Shareware Library is presently being updated and integrated within the PC-shareware links. This work is supervised by the PC-software working group within the FDSN working group on software. Presently, the library contains close to 200 entries from about 20 countries with a major contribution from the United States. The Seismological Software Library is also expected to play a significant role in developing future OO software in seismology, specifically in Java and CORBA.

87 – Global Inventory of Seismographic Networks

This chapter documents and archives basic information about most of the worlds seismic networks and provides a valuable starting point for future seismotectonic and hazard studies. Each network was asked to respond to the following survey questions to provide important basic data, such as the duration of recording, the region monitored, the equipment used, and the seismologists and organizations involved. The chapter also includes survey questions, which include name, staff, geographical location, network code, institutions, stations, recording, data analysis, data availability and other products, new or proposed developments,approximate number of earthquakes, and acknowledgements.